Apparatus for stacking letters and like articles



J. WILLIAMS EIAL m 9 m Q 3 m 1k mm m H mm a M Q 2. m R 8 9 8R & m 11% hr1| J E. all?! T i a April 11, 1956 APPARATUS FOR STACKING LETTERS ANDLIKE ARTICLES Filed June 29, 1951 April 1956 J. WILLIAMS EI'AL APPARATUSFOR STACKING LETTERS AND LIKE ARTICLES I Filed June 29, 1951 4Sheets-Sheet 2 April 17, 1955' J. WILLIAMS ET AL APPARATUS FOR STACKINGLETTERS AND LIKE ARTICLES 4 Sheets-Sheet 3 Filed June 29, 1951 f amw fav5 fl/ v w f ww 6 M e f 5 2 V p 1956 J. WILLIAMS ETAL Filed June 29, 1951APPARATUS FOR STACKING LETTERS AND LIKE ARTICLES i James i Williams,Sidcup, and Stewart Glover, Harrow, England,"assignors to Hall TelephoneAccessories Limlied, London, England .1 Application June 29, 1951,Serial No. 234,254 a Claims priority, application Great Britain July 5,1950 8 Claims. Cl. 271-64 This inventionrelates to apparatus forstacking, letters, cards, thin packets, cheques andlike articles,hereinafter referred to as letters, which are ejected or fed one by onein a generally vertical orientationancl, for example, by a generallyhorizontal movement in a'plane normal to the plane of the letter, from amachine or other device for handling or treating the letters. Suchamachine may, for example, be a starnpcancelling machine or sortingmachine.

The object-of the invention is to facilitate the formation of fiatarticles such as letters into a stack as they are fed from a conveyorbelt forming part of postal sorting equipment dealing With largequantities of spaced letters.

According to the present invention, the letters to be stacked are passedbetween stack-feeding rollers rotating at a peripheral speed which is.less than the speed at which the letters travel towards thestack-feeding rollers and the letters thereby presented for engagementby a projecting portion or portionsoffiat least one rotating member anda stack-supporting means to cause the letters to form a stack.

' letter-stacking member which rotates about an upwardly extending axisand co-operates with an abutment or stop Guide means are provided tocause the letters to .ap-

proach the stack-feeding rollers and rotating letterstacking member ormembers in therequired manner.

According to one feature of the invention, the rotating letter-stackingmember or each such member may comprise a substantially disc-like memberhaving at least one portion of its peripheral edge projecting so as tothrust against the faces of the letters. opposed thereto andforce eachletter in tu'rn into the stacking position.

Alternatively, an elongated roller with an appropriately contouredperipheral surface may be used instead of a plurality ofdisc-likeletter-stacking members.

.In order that the invention may be clearly understood and readilycarried into effect, one constructional embodiment thereof willhereinafter be. described by way of example and with reference to theaccompanying drawings in which: v i Fig. 1 is a part broken away fromelevational viewof a stacking unitcomprising three stacking ordestination boxes and means adapted to operate inaccordance with thepresent invention for stacking'letters therein; k

Fig. 2 is a plan view thereof; Fig. 3 is an end elevational view lookingin the directi'on of the arrow III (Fig. l); Fig. 4 is an elevationaldetail view, drawn toa'larger scale, of a "single destination box andthe letter stacking mechanism associated therewith shown diverting aletter to the destination box; while i V Q Fig. 5 is a view similar toFig. 4 but showing a dif. ferent operative stage in feeding the divertedletter to the stacking position.

As shown in Figs. 1,2 and 3, the stacking unit is mounted upon arectangular base structurecomprising a horizontal front rail 2 ofinverted L-sectibnahd hori zorital rear rail 3'of doubleangle sectioncon- 1 2 nected-together by anglesection end rails 1 so that the upperflanges of the front and rear rails lie in a common horizontal planetosupportdestination boxes 6, 7 and 8. Each destination box is formed by asubstantially rectangular horizontal floorfl bounded on one side by .a

narrow upstanding guide will 5 and upon the opposite side by a verticalwall or stop plate 9 and the rear end angle between the side walls ofthe box for a purpose,

hereafter described. p

Each plate 11 is carried in an upright position by a cranked bracket arm12 which is rigidly secured to and extends upwards from a sleeve 13mounted to slide upon a slide bar 14. Each slide bar 14 extends paralleland longitudinally with respect to the fioor of the corre: spondingdestination box and is mounted therebeneath in the base frame structure.Each sleeve 13 carries a blade spring 15 (Fig. 3) ad justably secured tothe sleeve by set screw means 21 and having its free end inwardly bentand notched to drag along the bar 14 and act as a friction brakethereon.

The stack-supporting plates ll each have a grip or handle 22 fixedthereto to provide'a means formanually swinging the stack-supportingplateabout the longitudinal. axis of the slide bar, thus to move theplate clear of the destination box and away from the front end of thestack of lettersin th'e'destination box, when it is desired toremove'the letters. The bottom edge of the plates 11 are suitably cutaway to clear the top edge of the low side wall 5 as they are swung outof and into the stackengaging position.

The rear end wall of each destination box is completed by a plate 16which is offset from the rear end'of the side wall 5 of the destinationbox and extended to form one upwardly extending wall 17 of a guideway18-leading to the rear end of the box. The opposite upright wall of eachguideway 18 is formed by the inwardly diverted end 19 of a fenceplateztl extending above and "parallel to the 'rear horizontal rail 3.

Pairs of diverting rollers 23, mounted to rotate about vertical axes,are disposed at the-points of defiectionof the guidewaywalls 19. fromthe fence;p'lates'20, i. e. at the letter-receiving mounts of theguidew'ays 18, so that the travelling peripheral surfacesof the rollers23project outwards through clearance slots providedin the correspondingcurved faces of the 'guidewaywalls 18. Each pair of rollers 23is-mounted upon avertical driven spindle 24 which is mounted uponandextends upwards frornthe disposed at the exit end of each guideway18, in diag onally opposite relation to the diverting rollers 23, toform a feed throatthrough which the letters are positively fed to the.corresponding destination box." Although not shown in the drawings, theaxis of the' roller 29 is pref.-

erablyslightly offset from that .of the roller 28 in the ,directionoftravelofqincoming letters, the purpose being Patented, Apr. 17, 1956tesp'eedup the swinging round of the tail of a letter passing-throughthese rollers, out of the'path of a following letter.

The rollers 28 of each stack-feeding pair is fixed to a vertical spindle30' which is mounted upon the top of the corresponding gearset casingand has a sprocket (not shown) fixed to the lower end thereof andmeshing with the driving gearset. The gear ratios ofthe driving gearsetsare selected to drive the stack-feeding rollers 28 at a peripheral speedwhich is approximately one third of the peripheral speed of thediverting rollers 23.

The co-operating roller 29 of each stack-feeding pair is mounted freelyto rotate in a bearing bracket 31 which is carried upon a grid-likestructure disposed at the front endof each guideway 18. Each grid-likestructure comprises a series of horizontal frames 32 fixed in'vertically spaced relation upon a vertical post 33 which is mounted uponand extends upwards-from the rear rail 3. The grid like structures aredisposed so that the outer side of each frame 32 thereof normallyextends in parallel, slightly offset relation to the rear walls 10, 16of the destination box associated therewith; The outer sides of the gridframes 32 thus form a flat grid with which the letters are brought intocontact, upon being diverted through the guideways 18, and therebyre-directed to travel in a direction parallel to the longitudinal rearfences of the unit, 1'. e. at right angles to the longitudinal sidewalls of the destination boxes. The grid-like structure of the letterre-directing means prevents the impedance of the letters by airresistance in being swung towards the said re-directing means.

The roller 29 of each stack-feeding roller pair is disposed to projectfrom between the spaced grid frames 32 so' as to co-operate with thepositively driven roller 28 of the pair and the grid-like structures areadapted to pivot about their posts 33 to permit the rollers 29 to moveaway from the rollers 28 so as to yield to the passage of letters ofvarious thicknesses between the rollers. Loading spring means 33a areprovided for yieldingly maintaining the grid-structures in the normalletter re-directing positions. 7

Rotary letter-stacking devices 34 are disposed at the rear ends of thedestination boxes to engage the letters as they leave the stack-feedingrollers and force the letters forwardly along the boxes in stackformation. Each device 34comprises three co-axial vertically spacedhorizontal discs 35 fixed upon a spindle 36 which is mounted upon andextends vertically upwards from the top of the corresponding gearsetcasing 25, behind the rear walls 10,

16 of the destination box; thelower end of the spindle projecting intothe casing and carrying a sprocket (not shown) which drivingly meshes inthe gearset.

Each disc 35 is shaped so that its edges form a regular polygon, e. g. ahexagon, with the corners 35a thereof rounded with curves ofcomparatively small radius. The fiatted edges of the discs are smoothfinished and the rounded corners thereof preferably highly polished sothat the rotating edges of the discs which project through clearanceslots in the rear walls 10, 16 of the destination box, can beengagedwith the letters and'the rounded corners 35a of the disc'causedto further the movement of the letters without in any way damaging theletters.

Alternatively, an elongated bar-or tube of hexagonal, octagonal or anypolygonal cross section'may be used in place of a plurality of thedisc-like members 35, providing that,- in equipment including severaldestination boxes, the diverting rollers of afollowing stacker areaccommodated.

I-n-t-he operation of the above described letter-stacking unit theletters are conveyed thereto by a horizontal travelling'conveyor belt 37which travels from end to end of the letter stacking unit and incl'oseproximity and parallel relatiori'to the rear fences thereof.-Thus', the conveyor belt 37 travels :in' the "direeti'oh o'f the arrow A(Fig. 2) past the rearwardly opening letter-receiving mouths of theguideways 18 and its direction of travel is at right angles to the sidewalls of destination boxes so that the letters L, which are carriedthereon in substantially erect edgewise position, approach and pass eachpair of deflecting rollers 23 prior to passing across the rearwardly'opening mouth of the guideway 18 associated therewith.

Electro-magnetically operated letter-diverting devices which may bemanually operated to sort letters into various stacks at the will of theoperator are provided to divert the letters L from the conveyor belt 37.Each diverter device comprises a substantially vertical vane or blade.38 fixed to: a pivotally mounted spindle 39 disposed upon the outer orrear side of the letter conveyor belt at a point adjacentto the rearmouth of the corresponding guide way 18, so that the vane or blade mayeither be withdrawn from and clear of the conveyor belt (as shown in thecase of the two end diverter blades in Fig. 2) or swung. across theupper face of the conveyor belt was to intercept and divert the letterscar ried upon the conveyor belt (as shown in the case of theintermediate vane or blade, Fig. 2). The length of each diverter vane orblade is such that the free end thereof extends past and is brought intoletter-engaging relation to the outwardly projecting peripheral edges ofthe defleeting rollers 23 when thevane or blade is swung into theletter-diverting position. I

Thus, a letter L brought into contact with a letterdiverting vane orblade 33, as shown in larger detail in Fig. 4, will be diverted totravel between the diverting blade and positively driven deflectingrollers 23 which are driven at a peripheral speed equal to the speed oftravel of the letterconveyor belt 37. The letter will thereupon bepositively driven through the guideway 18 and towards the stack-feedingrollers 28, 29 which will engage the leading end of the lettertherebetween after the said letter has passedbetween and clear of thedeflecting rollers'23 and diverting blade 38. The relative dispositionof the rollers 28, 29 and outer bars of the grid structures 32 is suchthat the trailing end part of the letter engaged between the rollers 28,29 is swung against the grid members and the letter thereby re-directedto travel in the same direction and in a'path parallel to its directionand path of travel prior to being diverted from the letter conveyorbelt.

The letter will leave the stack-feeding rollers and pass into thedestination box at a speed which is considerably less than the speed ofapproach to the stack-feeding rollers. Thus, the letter-divertingarrangement above described enable tiling of the letters to be achieved.That is to say, if theletter L passing between the stack-feeding rollers28, 29 is followed by another letter L1 immediately diverted from theletter conveyor and towards the same destination box, as shown. in Fig.5, the leading end' of the second letter L1 will neatly overlap the rearend of the first letter L before the latter is engaged by theletter-stacking discs 35. i g

On leaving the rollers 28, 29, the leading end of the letter L will moveinto engagement with the moving peripheral edges of the letter-stackingdiscs (as shown in Fig. 4), and will be deflected forwards and thenengaged by the rounded corners 35a of each rotating disc which willfurther the movement of the letter towards the oppos'ite side wall orstop plate 9 of the destination box when the letter has passed clear ofthe stack-feeding rollers. In this manner, the leading end of the letteris brought up against the side wallor stop plate of the destination boxinto which it is fed. The discs 35 will also act to pressthe letterforwards against the slidable stack-supporting plate 11 or against therearmost letter of the letters alreadystack'ed against the plate 11.

The trailing ends 'of the letters stacked against the inclined plate 1 1;are' forwardly offset from the path of travel of the followingincor'nifig letters", as shown in 2,

which obviates the risk .of the leadingendof anincorning letter beingtforced underthetrailing'end of the rearmost stackedletterh Theletters'thus stacked ag a inst. the stack-supporting I A plate 11 by the.combined efforts'of. the letter-stacking discs 35 and sidewall or.stopplate 9gradually force the plate 11 forwards against the braking effectof the spring 15 pressing against the slide bar 14 until the plate 11reachesthe limit of its forward displacement or, for other -1'3SOI1S, itis desired to remove the stacked letters from the destination box. Theplate 11 is then swung upwards and away from the destination box by ahand applied to Q the grip or handle 22, and the stack of letters thenremoved from the front of the box.

As clearly shown in Fig. 2, the opposite extremities of the stackingunit are provided with complementary parts of a stacking box andassociated letter diverting and stacking means and are adapted to becoupled together so that two or more of the units may be assembled inline to increase the number of destination boxes available to receiveand stack letters diverted from one and the same conveyor belt and themeeting ends of any two units so coupled together will combineto form adestination box complete with associated letter-diverting and. stackingmeans.

Although the invention has been more particularly described above withreference to a construction in which the letter conveying and supportingsurfaces are substantially horizontal, it will be understood that theinvention can also be carried into effect with other forms of apparatusin which the letter supporting surfaces are inclined to the horizontal.

We claim: 31. Apparatus for receiving letters supported edgewise upon,and selectively diverted from, a moving letter conveyor means and forstacking the diverted letters edgewise in a stacking box, comprising aguideway leading from v the said conveyor means to the stacking box, adiverting roller positioned at the entrance to the guideway adjacent theconveyor means and adapted to co-operate with a diverter device having avane or blade movable from a first position extending to one side of andin thedirection of movement of the conveyor means, to a second positionextending across the conveyor means and engaging the said divertingroller, means for rotating the diverting roller so that the peripheralspeed thereof is substantially equal to that of the conveyor meanswhereby a letter travelling on the said conveyor means is deflected bysaid vane or blade in the said second position to be engaged between thevane or blade and the. diverting roller and thereby discharged into theguideway, a pair of stack feeding rollers positioned at the exit of theguideway adjacent the stacking box, the said stack feeding roller beingrelatively displaceable and adapted to receive the letter therebetwe ento feed the letter into the stacking box in a direction transverselythereof, and means for rotating the said stack feeding rollers inopposite directions at a peripheral speed less than that of thediverting roller whereby a letter discharged into the guideway by saiddiverting roller at the speed of the conveyor means is fed into thestacking box at a reduced speed, the saidstacking box comprising anelongated stack supporting floor extending lengthwise laterally of theconveyor means in the 1 plane thereof upon which floor the letters arestacked an upwardly extending axis in the path of a letter fed to thestacking box by the stack feeding rollers so that "the said memberengages the letters as they are fed into the stacking box and urges eachletter in turn along the letter into engagement with the saidlonigtudinally extend-.

ing abutment.

2. Apparatus :as. claimed in claim 1, wherein the said guideway isinclined-to the longitudinal direction of the said stacking box and tothe direction of travel of the said conveyo'r'means so that thedirection of travel of each said" letter is changed when it is divertedfrom the said conveyor means, a letter re-directing means being disposedbetween the said diverting roller and said stack feeding rollers tore-direct the said diverted letters to travel in a direction at rightangles to the longitudinal direction of the said stacking box whenengaged by the said stackfeeding rollers.

3 Apparatus as claimed in claim 1, wherein said guideway is inclined tothe longitudinal direction of the said stacking box and to the directionof travel of the said conveyor means so that the direction of travel ofeach letter is changed when it is diverted from the said conveyor means,and a letter re-directing means is disposed between the said divertingroller and said stack-feeding rollersto redirect the diverted letters totravel in a direction at right angles to the longitudinal direction ofthe said stacking box when engaged by the said stack-feeding rollers,said letter re-directing means comprising a gridlike structure whichensures that the movement of the letters towards the said letterre-directing means is not impeded by air compression there-between.

roller with an appropriately contoured peripheral surface.

6. Apparatus as claimed in claim 1, wherein said guideway is inclined tothe longitudinal direction of the said stacking box and to the directionof travel of the said moving conveyor means so that the direction oftravel of each said letter is changed when it is diverted from the saidmoving conveyor means, and a letter re-directing means is disposedbetween the said diverting roller and said stack-feeding rollers tore-direct the said diverted letters to travel in a direction at rightangles to the longitudinal direction of the said stacking box whenengaged by the said stack-feeding rollers, said letter re-directingmeans being displaceable and carrying one of the said stack-feedingrollers so that the said letter re-directing means is moved by the saidone stack-feeding roller when the. latter is displaced relatively to theother said roller of the stack-feeding pair upon engagement of a lettertherebetween.

7. Apparatus as claimed in claim 6, wherein the said letter re-directingmeans comprises an openwork letter redirecting structure disposedbetween the said diverting roller and said stackfeeding rollers andforming in conjunction With the said stack-feeding rollers a dischargethroat through which the letters pass to the said stacking box, saidre-directing structure being mounted to pivot about an upwardlyextending axis and having the said displaceable roller of the saidstack-feeding pair mounted therein so that the said letter re-directingstructure is reorientated when the said displaceable stack-feedingroller is displaced relatively to the other roller ofthesaid'stackfeeding pair, thereby to cause the said diverted letters totravel in a direction at right angles to the longitudinal direction ofthe saidstacking box when engaged by the

